Abstract: A hydrogen gas separation method utilizing PSA process employs a plurality of adsorption towers A, B, C loaded with an adsorbent for separating the hydrogen gas from a hydrogen-containing gas mixture, and a cycle including introducing the gas mixture into the adsorption tower, adsorbing unnecessary gas in the gas mixture by the adsorbent, leading out product gas having high hydrogen concentration from the adsorption tower, desorbing the unnecessary gas from the adsorbent, and leading out desorbed gas containing the unnecessary gas and residual gas in the adsorption tower from the adsorption tower, is repeated. The adsorbent includes an activated carbon-based first adsorbent D located on the upstream side of the flow direction of the gas mixture in the adsorption tower with an filling ratio of 60 to 80%, and a zeolite-based second adsorbent E located on the downstream side of the flow direction with filling ratio of 40 to 20%.

Abstract: A method is provided for separating hydrogen gas from a mixed gas obtained by autothermal reforming reaction of hydrocarbon-based material in which air is added. In this method, by pressure swing adsorption using adsorption towers (A-C) each filled with an adsorbent, a cycle is repeatedly performed, including an adsorption step of introducing the mixed gas into the adsorption tower to adsorb unnecessary gas contained in the mixed gas by the adsorbent to discharge product gas with high hydrogen gas concentration from the adsorption tower, and a desorption step of desorbing the unnecessary gas from the adsorbent to discharge the unnecessary gas from the adsorption tower.

Abstract: The invention provides an off-gas feeding method that supplies the off-gas discharged from a plurality of adsorption towers (A, B, C) to an off-gas consumption unit (1), when performing a pressure swing adsorption process of repeating a cycle including a plurality of steps, to enrich and separate the target gas out of a gas mixture in the adsorption towers (A, B, C) loaded with an adsorbent. The method allows at least one of the plurality of adsorption towers (A, B, C) to discharge the off-gas, in all the steps included in the cycle, so as to continue to supply the off-gas to the off-gas consumption unit (1) without interruption.

Abstract: The invention provides an off-gas feeding method that supplies the off-gas discharged from a plurality of adsorption towers (A, B, C) to an off-gas consumption unit (1), when performing a pressure swing adsorption process of repeating a cycle including a plurality of steps, to enrich and separate the target gas out of a gas mixture in the adsorption towers (A, B, C) loaded with an adsorbent. The method allows at least one of the plurality of adsorption towers (A, B, C) to discharge the off-gas, in all the steps included in the cycle, so as to continue to supply the off-gas to the off-gas consumption unit (1) without interruption.

Abstract: The present invention is a gas separation method using a plurality of adsorption columns packed with an adsorbent. A cycle including a series of steps (adsorption, first pressure reduction, second pressure reduction, desorption, scrubbing, and repressurization) is repeated in each adsorption column. In the adsorption step, a gas mixture (G1) is introduced into a column (A) so as to cause the adsorbent to adsorb unnecessary components, and a product gas (G2) is led outside of the column (FIG. 3A). In the first pressure reduction step, the internal pressure of the column (A) is reduced by lead-out of a gas (G3) (FIG. 4A). In the second pressure reduction step, the internal pressure of the column (A) is further reduced by lead-out of the gas (FIG. 4B). In the desorption step, the unnecessary components are desorbed from the adsorbent and purged from the column (A) (FIG. 4C). In the scrubbing step, introduction of the gas (G3) and purging of the gas (G4) are performed simultaneously (FIG. 5A).

Abstract: Product gas (Gpro) is separated from material gas (Gmat) by a PSA process utilizing a plurality of adsorption towers (A-C) each loaded with an adsorbent. The separation of the product gas (Gpro) is performed by repeating a cycle comprising an adsorption step, a decompression step, a desorption step, a cleaning step and a pressurization step. In the decompression step, remaining gas (Grem) as cleaning gas is introduced from one adsorption tower (C) to another adsorption tower (B). The amount of the remaining gas (Grem) introduced is 2 to 7 times the volume of the adsorbent loaded in the adsorption tower (B) as converted into volume at common temperature and under atmospheric pressure. To remove both of carbon monoxide and carbon dioxide from the material gas (Gmat) by a single kind of adsorbent, use is made of zeolite having a faujasite structure with a Si/Al ratio lying in a range of 1 to 1.5 and a lithium-exchange ratio of no less than 95%.

Abstract: A method is provided for separating object gas from mixed gas using a plurality of adsorption units each of which is loaded with an adsorbent. In each of the adsorption units, a cycle is repetitively performed which includes a step for introducing mixed gas into an adsorption unit (1) for adsorbing unnecessary gas by the adsorbent for outputting product gas from the adsorption unit, a step for desorbing the unnecessary gas from the adsorbent, and a step for cleaning the adsorption unit. The adsorption unit (1) includes a first sub-unit (1a) with a product gas outlet (1d) and a second sub-unit (1b) with a mixed gas inlet (1e). In the desorption step, the first and the second sub-units (1a, 1b) are brought into mutually non-communicating state, while the mixed gas inlet (1e) of the second sub-unit (1b) is opened.

Abstract: Product gas (Gpro) is separated from material gas (Gmat) by a PSA process utilizing a plurality of adsorption towers (A-C) each loaded with an adsorbent. The separation of the product gas (Gpro) is performed by repeating a cycle comprising an adsorption step, a decompression step, a desorption step, a cleaning step and a pressurization step. In the decompression step, remaining gas (Grem) as cleaning gas is introduced from one adsorption tower (C) to another adsorption tower (B). The amount of the remaining gas (Grem) introduced is 2 to 7 times the volume of the adsorbent loaded in the adsorption tower (B) as converted into volume at common temperature and under atmospheric pressure. To remove both of carbon monoxide and carbon dioxide from the material gas (Gmat) by a single kind of adsorbent, use is made of zeolite having a faujasite structure with a Si/Al ratio lying in a range of 1 to 1.5 and a lithium-exchange ratio of no less than 95%.

Abstract: A process is provided for recovering oxygen-rich gas by enriching gaseous oxygen contained in crude gas by a single-tank PSA process which utilizes a single adsorption tower loaded with an adsorbent. A cycle is repeated including introducing crude gas into the adsorption tower, desorbing unnecessary components from the adsorbent, introducing washing gas into the adsorption tower for discharging the remaining gas from the adsorption tower, and raising the internal pressure of the adsorption tower. The desorbing includes recovering semi-enriched oxygen gas existing in the adsorption tower after finishing of the adsorption for retention in a recovery tank. The introduction of washing gas includes introducing part of the semi-enriched oxygen gas existing in the recovery tank into the adsorption tower as the washing gas. Raising the internal pressure includes introducing the rest of the semi-enriched oxygen gas retained in the recovery tank into the adsorption tower.

Abstract: A process is provided for recovering oxygen-rich gas by enriching gaseous oxygen contained in crude gas by a single-tank PSA process which utilizes a single adsorption tower (1) loaded with an adsorbent. In the process, a cycle is repeated which includes an adsorption step of introducing crude gas into the adsorption tower (1), a desorbing step of desorbing unnecessary components from the adsorbent, a washing step of introducing washing gas into the adsorption tower (1) for discharging the remaining gas from the adsorption tower (1), and a pressurizing step of raising the internal pressure of the adsorption tower (1). The desorbing step includes recovering semi-enriched oxygen gas existing in the adsorption tower (1) after finishing of the adsorption for retention in a recovery tank (3). The washing step includes introducing part of the semi-enriched oxygen gas existing in the recovery tank (3) into the adsorption tower (1) as the washing gas.

Abstract: In a process of recovering oxygen-enriched gas by pressure swing adsorption with use of adsorbers (A, B) each packed with an adsorbent which selectively adsorbs nitrogen from a gas mixture mainly containing nitrogen and oxygen, recovery of remaining oxygen-enrich gas is fully carried out by pressure equalization between both adsorbers (A, B), and a vacuum pump (8) is always connected to either adsorber (A or B) for continuous evacuation of nitrogen. For this purpose, the pressure equalization between both adsorbers (A, B) is conducted at least in two steps wherein one adsorber (A or B) is pressurized, whereas the other adsorber (B or A) is pressurized, so that recovery of oxygen-enriched gas is possible until there is substantially no pressure difference between both adsorbers (A, B).